In the case of the termination of any benefits available to an employee under this subchapter on the grounds such employee declined a reasonable offer of a position the grade or pay of which was equal to or greater than his retained grade or pay, such termination may be appealed to the Office of Personnel Management under procedures prescribed by the Office.
(2) Nothing in this subchapter shall be construed to affect the right of any employee to appeal—
(b) For purposes of any appeal procedures (other than those described in subsection (a) of this section) or any grievance procedure negotiated under the provisions of chapter 71 of this title—
any action which is the basis of an individual’s entitlement to benefits under this subchapter, and
shall not be treated as appealable under such appeals procedures or grievable under such grievance procedure.